As a result of revolutionary progress that has been made in ink jet recording technology in recent years, images output onto recording media by ink jet printing have shown improved high quality, so that the output of high-quality images comparable to silver halide photographs is now possible. However, the dye inks constituting the ink jet recording inks that are used for the output of high-quality images suffer from the following drawback: specifically, such inks tend to discolor or fade over time as a result of exposure to ultraviolet light, visible light, moisture, heat, nitrogen oxide gases, ozone gas and the like. Accordingly, printed matter recorded by ink jet recording using dye inks is inferior in terms of light resistance, water resistance and gas resistance, so that deterioration in recorded images such as discoloration and the like occurs in ordinary environments such as mounting on interior walls. Consequently, such printed matter still does not equal silver halide photographs in terms of storage characteristics (prevention of deterioration).
Furthermore, so-called absorption type media which have an ink receiving layer that contains a fine porous material such as amorphous silica or the like constitute the mainstream of ink jet recording media, and there has been a tendency for even finer materials to be used as such porous pigments in order to achieve a higher image quality. However, when such porous pigments are made even finer, the specific surface area is proportionally increased, so that the contact between the porous pigment in the ink receiving layer and the outside air increases; as a result, there is a danger that the storage characteristics of such printed matter, and especially the gas resistance, will deteriorate.
Furthermore, although ink jet recording materials themselves have reaches a fairly satisfactory standard in terms of water resistance in recent years, there are still problems regarding the light resistance and gas resistance of such materials. For example, techniques for improving the light resistance and gas resistance of ink jet recording materials include techniques in which the light resistance and gas resistance of the ink receiving layer itself that constitutes the ink jet recording medium are improved (see Japanese Patent Application Laid-Open No. H9-254526, Japanese Patent Application Laid-Open No. H8-164664, Japanese Patent Application Laid-Open No. H5-221115 and Japanese Patent Application Laid-Open No. H7-246769), and techniques in which a film, resin layer or the like which possesses light resistance and gas resistance is laminated on the image surface (see Japanese Patent Application Laid-Open No. H8-252985, Japanese Patent Application Laid-Open No. H8-252883, Japanese Patent Application Laid-Open No. H5-318943, Japanese Patent Application Laid-Open No. H8-174989, Japanese Patent Application Laid-Open No. H8-207429 and Japanese Patent Application Laid-Open No. H9-174995); however, none of these techniques can endow ink jet recording media with sufficient light resistance and gas resistance.
Furthermore, methods in which the recorded surface is coated with various treatment liquids in order to improve the water resistance and light resistance of the recorded surface are described in (for example) Japanese Patent Application Laid-Open No. S57-69054, Japanese Patent Application Laid-Open No. S56-77154, Japanese Patent Application Laid-Open No. S55-150396, Japanese Patent Application Laid-Open No. H2-80279 and Japanese Patent Application Laid-Open No. H2-194958. However, in the methods described in these patent applications, the 1treatment liquid coating process requires manual work or the like following the formation of the recorded surface, so that the methods are inconvenient.
Furthermore, a method in which a material that improves the storage characteristics is used as a treatment ink, and this material is written over the recording ink in order to improve the water resistance, light resistance and writing characteristics of the recording medium is described in Japanese Patent Application Laid-Open No. S58-128862. Moreover, a printing method in which the water resistance and light resistance are improved by spraying and immediately mixing a first liquid (which contains at least a coloring component) and a second liquid, and then fastening and fixing [this mixture] on a transfer-receiving body, is described in Japanese Patent Application Laid-Open No. H3-240557. However, since the protective effects of treatment agents vary according to the type of recording medium involved, a treatment liquid that is suitable for the type of recording medium involved must be selected in order to achieve an appropriate manifestation of the protective effect of the treatment liquid.
As was described above, dye inks suffer from the drawback of susceptibility of discoloration and fading over time as a result of exposure to ultraviolet light, visible light, moisture, nitrogen oxide gases, ozone gas and the like; furthermore, ink jet recording media suffer from the drawbacks of poor light resistance and poor gas resistance. Consequently, printed matter recorded by ink jet recording using such dye inks on such ink jet recording media is especially prone to problems in terms of light resistance and gas resistance.
Accordingly, an object of the present invention is to provide a surface treatment method for recorded matter which makes it possible to improve in a simple manner the light resistance, gas resistance, water resistance, moisture resistance, resistance to thermal yellowing, plasticizer resistance and the like of recorded matter in which images are recorded on a recording medium, as well as improving the luster and friction resistance of such recorded matter, and also to provide a surface-treated product [treated] using this method, and a surface treatment apparatus.
Furthermore, another object of the present invention is to provide a surface treatment apparatus which allows the easy and stable performance of a surface treatment for the purpose of protecting formed images.
Furthermore, another object of the present invention is to provide a surface treatment apparatus which allows the easy surface treatment of the recorded surface by selecting a treatment agent that is suited to the type of recording medium such as glossy paper, matte paper or the like.